Polymeric film substrates may be coated with various materials to impart various desired properties to the substrates. These properties include, but are not limited to, sealability, water and grease resistance, adhesion, and tear or puncture resistance. In some instances, the coating materials may incorporate metals or metal oxides. These types of coatings are particularly important in the flexible packaging industry which may utilize polymeric film substrates. Packaging items such as pouches and bags used for storing food may involve polymeric film substrates. In these items, barrier properties may be desired in the polymeric film substrates to improve durability of the package and quality and shelf life of the package contents.
Metal and metal oxide coatings are used to improve the barrier of plastic films used in packaging. However, the performance of these coatings tends to diminish during processing of the film. For example, the film is kept under tension when it is wound and unwound during printing and lamination processes. The tension can cause cracking of the coatings deposited on the film. Additionally, the surface of the film is also in contact with rollers and guides that can abrade and scratch the coatings. These damages to the coating can affect the barrier properties of the coated polymeric films with regards to water vapor and oxygen transmission rates.